Processes and Things

This article was inspired by Karl Popper's 1965 lecture[1]
Beyond the search for invariants. It complements another article by
me[2], inspired by Thomas Kuhn's 1959
lecture[3] The essential tension. In my previous
article I argued that Kuhn's sociological analysis of the
tension between `normal' and `revolutionary' science actually
reflects a philosophical tension between two rival modes of
analysis of physical processes. Now I see that these two rival
modes have been explored extensively in Popper's lecture, where
he traces them back to the beginnings of Western philosophy.
Crudely speaking, Popper describes the tension between the
unchanging `block universe' of Parmenides and the constantly
changing universe of Heraclitus. However, Popper considers
that this crude description does not do justice to the very
rich Parmenidean picture. Indeed, for him, Parmenides was
the first to pose, in modern terms, what we understand as
the Problem of Change in physics, and he tries to relate
the Parmenidean `solution' to this problem to the more
recent attempts of Boltzmann, Einstein and Schrodinger.
Popper's lecture raises many fascinating questions. In the
area of Classical Philosophy, one may question whether the
atomism of Democritus and Lucretius, and thence Boltzmann,
came from Parmenides or from Heraclitus. In
Philosophy of Science, one may,
following Popper's own line of investigation, ask
whether thermodynamic irreversibility can possibly be
explained in Boltzmann's atomistic, and Parmenidean,
world.

Popper states the Problem of Change as follows

All change is change of something. There must be a
thing that changes; and that thing must remain,
while it changes, identical with itself. But if,
we must ask, it remains identical, how can it ever
change?.

The question seems to reduce to absurdity the idea that any particular
thing can change.

A green leaf changes when it becomes brown; but not if
we replace it with a brown leaf; it is essential for
change that the changing leaf remains the same during change.
But it is also essential that it becomes something else:
`it was green, and it becomes brown; it was moist, and
it becomes dry; it was hot, and it becomes cold.'

In the universe of Parmenides there is no change.
He achieves change only by making what
Popper calls a Parmenidean Apology (PA), which
actually destroys the whole
Parmenidean programme. Just as Parmenides refuted the
programme of Heraclitus, so, says Popper, some element
of the Heraclitean programme must be deployed in order
to repair this breakdown. The classical atomists,
Democritus and Lucretius, are often classified as followers
of Heraclitus, but Popper classifies the
programme of their modern successor,
Ludwig Boltzmann, as Parmenidean. He locates the point
at which Boltzmann makes the PA, and proposes, instead
of Boltzmann's inadequate solution, a different solution
of his own. I shall try to show that Popper's solution
is a good one, and that, sufficiently developed, it may
solve the even more intractable problems associated with the
physics of our century, namely those described by Popper
in his book The Quantum Schism[4].

The Boltzmann problem

Boltzmann considered a mechanical system
consisting of a box of volume 2V divided, for times
t less than 0, into two equal volumes by a partition. In the
left-hand box there are N identical atoms
(I shall refer to "atoms" throughout, even
though, in modern terminology, it would be more correct
to say "molecules". The Greek atomists, of course, knew
nothing of this distinction, and, even nowadays, it still customary to
describe Boltzmann as an atomist, rather than a moleculist.)
whose total
energy is UL, and in the right-hand box there are
N identical atoms, of the same species as in the left-hand
box, whose total energy is UR which is less than UL.
Now suppose that, at t=0, the partition is removed,
and that, at some later time t1, it is replaced.
Then thermodynamics, which Popper classifies as a
non-Parmenidean discipline, says that the new
value of UL, that is UL(t1), is less than
UL(0), and that it is greater than
[UL(0)+UR(0)]/2. Of course this also means that
UR(t1) lies between UR(0) and
[UL(0)+UR(0)]/2;
there is a tendency towards the equipartition of
energy. We may, in analogy with Popper's leaf, say that
the `green' state [UL(0),UR(0)] changes into the `brown'
state [UL(t1),UR(t1)].

Boltzmann tried to explain this thermodynamic process
by assuming, at t=0, a certain (Maxwellian) distribution of speeds
and directions among the atoms on both sides of the partition.
He was then able, after making what he considered the
very plausible and reasonable additional Hypothesis of
Molecular Chaos (or Stosszahlansatz)[5], to explain the above
tendency to equipartition of energy.

This was a revolutionary claim by the young Boltzmann
- he made it in 1871, at the age of 27. It seemed to derive,
from an atomistic, therefore determinist and Parmenidean,
model of the gas, an evolutionary and irreversible
property which has been observed for real gases. Surely,
such a mode of explanation may now be used to explain
how green leaves turn brown? But his analysis was soon
challenged, first by his Vienna colleague Josef Loschmidt,
and later by Max Planck and Henri Poincare, all of whom
were in broad agreement with Boltzmann's atomism. This
crisis was, of course exploited by Boltzmann's philosophical
opponents, notably Ernst Mach, and there seems little
doubt that the subsequent psychological stress contributed
to his tragic death in 1906[6].

Essentially the Loschmidt refutation of Boltzmann's
argument is that we may, at the moment t=t1/2,
imagine that some mischievous demon intervenes in the
process and reverses the directions of motion of every
one of all the 2N atoms. In that case the whole gas
retraces, in reverse, between t=t1/2 and t=t1,
the evolution which had occurred between t=0
and t=t1/2, thereby recovering, at t=t1, the
state at t=0. On Boltzmann's definition of the
entropy, we may say that it increases from t=0 to
t=t1/2, in accordance with the observed thermodynamic
behaviour, but decreases from t=t1/2 to t=t1.
At this stage Boltzmann introduced his Stossszahlansatz,
in an attempt to argue that the state produced by the
demon's intervention was enormously less probable than
any of the 'naturally occurring' states, but all of his
efforts were unsuccessful.
To make matters worse, Ernst Zermelo, with the encouragement
of Max Planck[7], showed that, even without the intervention
of a demon, a Boltzmann gas must return arbitrarily closely
to its initial state within a certain (rather large)
time period.

The whole programme was fully
analysed, a few years after Boltzmann's death, by the
Ehrenfests[8], who had collaborated closely with
him during his latter years. As Popper puts it, Boltzmann's
Stosszahlansatz is an example of a PA; it is not only
incompatible with his atomistic model; it effectively
destroys that model; like any other purely
Parmenidean system, Boltzmann's gas cannot undergo change!

A Heraclitean solution to the Boltzmann problem

The problem about Boltzmann's gas is that it has a finite,
albeit large, number of degrees of freedom - 12N for a gas
of 2N molecules - and, as a related property, its total
energy is constant. The atoms of a real gas lose energy
whenever they collide, either with each other or with
the walls of the container. Thus there is a dissipation
process. This is compensated by a corresponding
fluctuation, which arises because,
in addition to the 12N atomic degrees of freedom,
there are an infinite number of degrees of freedom,
associated with the force fields involved in the
collisions. It is a general Law of Nature that
these two types of process are a complementary pair,
and their joint effect is that, in a real gas as opposed
to a Boltzmann gas, individual atoms have only a very
short memory of their initial state. This means that
neither the Loschmidt nor the Zermelo mechanisms apply
in a real gas. The origin of the entropy increase lies
in this fluctuation-dissipation mechanism, and not,
as Boltzmann supposed, in any Law of Large Numbers
arising from the largeness of N.

But, we may ask, what is the origin of the
fluctation-dissipation mechanism? The point is
that atoms are not billiard balls, but are made
of positive and negative electric charges, which
radiate away energy in the form of electromagnetic
radiation whenever the atom undergoes a change
of its overall velocity. As Popper remarks in his
lecture, it is a property of radiation that it
always propagates as an outgoing spherical wave,
and never as an ingoing wave. This enables
us to distinguish between a moving picture of a real
physical phenomenon (the outward wave), and the pseudophenomenon
which we see if the cinefilm is reversed. We may
now distinguish, with equal confidence, between
a cinefilm of 2N atoms, showing a sharing out
of an initially uneven energy distribution, and
the same film run backwards. For a more detailed
discussion of the latter process see
Refs.[9,10,11,12].

In summary we may say that the Atomists, from Democritus
to Boltzmann, tried to explain Change by the movement
of atoms. As Popper says, this was a noble endeavour
which ultimately failed. However, this
purely atomist programme may be repaired by
recognizing, alongside of the finite degrees of freedom
of the atoms, the infinite degrees of freedom of
the force fields. This means recognizing that
the motion of the atoms is inelastic. The
agent of irreversible change in Nature is, just as
Popper supposes, the outgoing nature of the radiation
fields.

A Heraclitean resolution of the Quantum Schism

The fluctuations of the electromagnetic field,
referred to in the previous section, are always
present, even at the absolute zero of temperature,
and must be taken into account whenever any object
containing electric charges undergoes acceleration.
This is something which profoundly affects the
whole question of Quantum Indeterminacy, for example
the Heisenberg Principle; since there are fluctuating
fields, the chaotic motion of subatomic particles no longer
has to be, as Niels Bohr claimed, unanalysable. In 1927, when
Einstein and others made the first objections to the
new quantum mechanics, the zeropoint fluctuations (ZPF)
had not been discovered; they became established as
a real phenomenon only in the late 1940s, with the discovery
of the Lamb shift and of the Casimir effect.

What has been
really difficult to understand is the unwillingness
of the scientific community to take account of the
ZPF[13], but now Popper's lecture gives
us some help with this problem also. As I indicated
in my earlier article[2], it is more of a
sociological than a scientific one, but now Popper
shows that it is also philosophical, and
furthermore of great antiquity. Popper classifies Quantum Mechanics (QM)
as Parmenidean, but in contrast to Boltzmann's atomism, which is
determinist and based on a realist metaphysics, QM is indeterminist
and based on an idealist metaphysics. Popper, following on his
criticism of Boltzmann, classifies himself as indeterminist
and realist. Indeed, to avoid any misunderstanding he said,
in a lecture of 1983[14], that he was, in
common with Boltzmann, a
metaphysical realist. But QM and Boltzmann share one most
important feature; they are both Parmenidean programmes,
that is they are closed systems with finite degrees of freedom.
When they fail to describe change, they try to escape
by making a Parmenidean apology, but, says Popper, this
is equivalent to conceding failure. The trouble is that,
having themselves failed, they do not wish their
Heraclitean rivals to succeed. Instead, like that other
great failed philosopher and clever mathematician,
Pythagoras, they go to great
lengths to hide their failure from the "ignorant"
public.

QM, as opposed to Quantum Field Theory, describes
static systems; as Schrodinger[15]
remarked, nothing ever happens in QM, because, in
a unitary time-evolution of the state function, the
only quantities which change are the phases of the
various stationary states. Thus QM exhibits its
Parmenidean nature.
It requires the intervention of an observer, through
the mechanism known as "collapse of the state function",
to produce a transition, and Popper has identified
this collapse mechanism as an example of a Parmenidean
apology (PA). Not surprisingly, given the long
history of the PA, stretching from Parmenides to
Boltzmann, a substantial group of physicists now find
this description unconvincing.

The crisis of confidence in QM has deepened since
the discovery by John Bell[16], in 1964, that the collapse
mechanism requires us to believe that a measurement
in one part of space can result in an instantaneous
change of the system in a distant part of space. Systems
in QM are said to be "entangled", a new buzzword which
could have been applied to all Parmenidean systems from
the very birth of western philosophy 2500 years ago!
Like lemmings, intent on not merely self-destruction,
but also the destruction of their own science, various
Parmenidean Young Turks have been claiming, ever since 1964,
to have found experimental evidence for entanglement[17,18,19,20],
but every time their logic, their experimental practice,
or their analysis of data has been shown to be faulty.

For a detailed indictment of this,
unfortunately widespread, bad science, I refer to my Internet
page[21]. Here I want to dwell on some more
positive aspects of the Bell programme, which I believe
could lead to a resolution of the Quantum Schism.
As I indicated above, the problem with QM lies in the M
rather than the Q. Like Popper, I label myself as indeterminist,
and I take the Q of QM to be shorthand for the underlying
stochasticity produced by zeropoint
fields. Thus it seems to me quite possible that Quantum
Field Theory (QFT), which does not have the Parmenidean
features of QM, will, properly developed, be found not
to exhibit nonlocal entanglement.

In this area I claim that my school (which we call
Stochastic Electrodynamics) has made some real scientific
progress. On the one hand we have been able to establish
close parallels between the formalism of Quantum Electrodynamics
(a branch of QFT) and Stochastic Electrodynamics
(SED)[13]. On the
other hand we have been able to show that all of the
Young Turks' experiments, referred to in the previous
paragraph, may be explained by normal, that is local,
electrodynamics once the role of the zeropoint field has
been recognized. Thus, by introducing the infinite
number of degrees of freedom present in the field,
SED can rescue QM from its stasis, in more or less
the same manner as it has already rescued the
Boltzmann gas. For details I again refer to my
Internet page, and to the extensive bibliography
quoted there.

It is, I think, crucial to recognize the
materiality or "thinginess" of the electromagnetic
field. As Popper says in his lecture, Parmenides
was the first to distinguish between things and
processes. But, with respect to light, Popper
makes a misclassification, in saying it is a
process rather than a thing. Commenting on the
"entanglement" experiments in 1979, Bernard
d'Espagnat[22] said

The doctrine that the world is made of objects
independent of human consciousness is in contradiction
with quantum mechanics, and with the results of recent
experiments.

As far as QM goes, d'Espagnat was correct; in the static
Parmenidean world of QM, no change occurs except through
the intervention of a (human) observer. But the objects,
or things, on whose capricious behaviour d'Espagnat was
commenting were the mythical atoms of light which he,
in common with a large uncritical community of theoretical
physicists, calls photons. In the analysis of SED,
photons have always been a doubtful concept, and this is
a view which Willis Lamb[23], the discoverer
of the Lamb shift and of the laser, shares. It turns out that all
of the phenomena, such as the photoelectric effect
and Compton scattering, which have been held up as
evidence for the quantization (that is,
atomization) of the light field,
have a much simpler explanation once we recognize
the reality of the ZPF. The electromagnetic field,
including this noisy ZPF substratum, is a real
physical object with an infinite number of degrees
of freedom. When this field interacts with any
distribution of electric charge - an electron, an atom
or a nonlinear crystal, for example - waves of different
frequencies are coupled together, that is scattering
occurs, with the outgoing frequencies different from
the ingoing.

The materiality of the electromagnetic field was
already established well over 100 years ago, by
scientists like Maxwell, Hertz, Heaviside and Lorentz.
In the course of establishing its materiality, a
distinction was made between light and heat; in
particular the Wave Theory of Heat, which had
a lot of support during the first half of the 19th
century[24], was superseded by the Kinetic
Theory championed by Boltzmann. This established
that heat is not a thing, but rather a process
among atoms, which, of course, are things. Light, by
contrast, is a thing. Precisely because it is a thing,
it requires no medium to facilitate its transmission;
this means that light waves are fundamentally different
from sound waves. Now the SED school is claiming that
full recognition of light's materiality will resolve
Popper's Quantum Schism, and thereby recover for
science a large body of knowledge which has
fallen temporarily into the hands of a magical
priesthood.